Questions about setting the 'background' of images (100% quick fix)_html/css_WEB-ITnose

Apply translucency to the image
.tit {
position: absolute;
left: 0;
bottom: 0;
height: 27px;
background : rgba(255,255,255,0.8) url(../images/bg-item-tit2.png) right bottom no-repeat;
background-size: auto 16px;
width: 100%;
overflow: hidden;
}

Problem: The "background" here is set to "right bottom" alignment. Changing it to "center center" has no effect. Why do we need to set the background alignment angle? ? ? Are there any such different cases that can be distinguished?

Reply to discussion (solution)

http://paranimage.com/css-background-attribute/ It’s very detailed

Just from a point of view,
If background-size doesn’t work, what do you think will happen?